The ground fault circuit interrupter (GFCI) is a leakage protection product widely used in countries/regions such as the United States, Canada, North America, and South America. It plays an important role in protecting safety of lives and property of the people in the aforementioned areas. An existing GFCI generally comprises a base, a cover with receptacle jacks, an electromagnetic tripping mechanism, a contact assembly, a grounding assembly, a power input connection assembly, a power output connection assembly, and other components. Its circuits include a power supply circuit, a ground fault detection circuit, a signal amplifying circuit, a power supply indicator circuit, a manual detection circuit, a reverse connection detection and execution circuit, and a tripping mechanism driving circuit. The electromagnetic tripping mechanism is controlled by the ground fault detection circuit. The GFCI can supply power to the load through the receptacle jacks in the cover, and can also provide power to the load connected thereof through the power output connection assembly. US patent application publications with the numbers US2013021120A1 and US2013038968A1 disclose the above conventional GFCI.
Due to existing restrictions on circuit design, the conventional GFCI suffers the following safety risks:
First, the conventional GFCI circuit lacks comprehensive reverse connection detection function. When an installer mistakenly makes a reverse connection of the power supply lines, the GFCI may not realize the function of leakage protection and fail to provide of ground fault protection. Accordingly, the conventional GFCI suffers installation risks, and it is difficult for a user to notice reverse connection of power supply lines.
Second, in a working state, the conventional GFCI carries out tests through a manual detection circuit. During use of a conventional GFCI after installation of the product, if a user wants to know whether the GFCI product is in a normal working state, he needs to press a button of the manual detection circuit to find out. Such a design requires the user to regularly make manual tests of the GFCI products. On one hand, this imposes heavier burden on the user; on the other hand, when the conventional GFCI product is damaged at work, the user may not notice it. After failure occurs in the conventional GFCI product, there are safety risks before the user notices that the GFCI product failed and replaces it.
Third, the power supply detection and indicator of the conventional GFCI has a simple structure. It can only indicate whether the GFCI product is energized. It cannot detect and indicate whether the GFCI product is in a normal working state, and thus fails to meet the fault detection requirement of the GFCI product.